Design and verification of long-running transactions in a timed framework

Long–running transactions consist of tasks which may be executed sequentially and in parallel, may contain sub–tasks, and may require to be completed before a deadline. These transactions are not atomic and, in case of executions which cannot be completed, a compensation mechanism must be provided. In this paper we develop a model of Communicating Hierarchical Timed Automata suitable to describe the mentioned aspects in a framework where also time is taken into account. We develop the patterns for composing long–running transactions sequentially, in parallel or by nesting. The correct compensation of a composed long–running transaction is preserved by these composition patterns. The automaton-theoretic approach allows the verification of properties by model checking. As a case study, we model and analyse an example of e–commerce application described in terms of long–running transactions.